the nefei ( label stuck in the top layer of tea) should help ID it if the wrapper is lost. Since lots of wrappers (cnnp) look (to me ) very much the same, even having the wrapper/nefei does not always serve to id the cake.

I have had the same problem with a few cakes that have very thin paper. The next time you put an order in from a vendor just ask if they have a few extra wrappers. Yunnan Sourcing and Puerhshop have them. I have gotten a few like that, or just contact a vendor and see if they will sell you some. I also had a tong in which the cakes had no wrappers so I used the extras after opening it.